(* checking *)
(* *)
(***************************************************************************)
-
-
-type elt = int
-
-type t = { id : int;
- key : int; (* hash *)
- node : node }
-and node =
- | Empty
- | Leaf of int
- | Branch of int * int * t * t
-
-module Node =
- struct
- type _t = t
- type t = _t
- let hash x = x.key
- let hash_node = function
- | Empty -> 0
- | Leaf i -> i+1
- (* power of 2 +/- 1 are fast ! *)
- | Branch (b,i,l,r) ->
- (b lsl 1)+ b + i+(i lsl 4) + (l.key lsl 5)-l.key
- + (r.key lsl 7) - r.key
- let hash_node x = (hash_node x) land max_int
- let equal x y = match (x.node,y.node) with
- | Empty,Empty -> true
- | Leaf k1, Leaf k2 when k1 == k2 -> true
- | Branch(p1,m1,l1,r1), Branch(p2,m2,l2,r2) when m1==m2 && p1==p2 &&
- (l1.id == l2.id) && (r1.id == r2.id) -> true
- | _ -> false
- end
-
-module WH =Weak.Make(Node)
-(* struct
- include Hashtbl.Make(Node)
- let merge h v =
- if mem h v then v
- else (add h v v;v)
+INCLUDE "utils.ml"
+module type S =
+sig
+ include Set.S
+ val intersect : t -> t -> bool
+ val is_singleton : t -> bool
+ val mem_union : t -> t -> t
+ val hash : t -> int
+ val uid : t -> int
+ val uncons : t -> elt*t
+ val from_list : elt list -> t
end
-*)
-let pool = WH.create 4093
-
-(* Neat trick thanks to Alain Frisch ! *)
-
-let gen_uid () = Oo.id (object end)
-let empty = { id = gen_uid ();
- key = 0;
- node = Empty }
-
-let _ = WH.add pool empty
-
-let is_empty = function { id = 0 } -> true | _ -> false
+module Make ( H : Hcons.S ) : S with type elt = H.t =
+struct
+ type elt = H.t
+
+ type 'a node =
+ | Empty
+ | Leaf of elt
+ | Branch of int * int * 'a * 'a
+
+ module rec HNode : Hcons.S with type data = Node.t = Hcons.Make (Node)
+ and Node : Hashtbl.HashedType with type t = HNode.t node =
+ struct
+ type t = HNode.t node
+ let equal x y =
+ match x,y with
+ | Empty,Empty -> true
+ | Leaf k1, Leaf k2 -> H.equal k1 k2
+ | Branch(b1,i1,l1,r1),Branch(b2,i2,l2,r2) ->
+ b1 == b2 && i1 == i2 &&
+ (HNode.equal l1 l2) &&
+ (HNode.equal r1 r2)
+ | _ -> false
+ let hash = function
+ | Empty -> 0
+ | Leaf i -> HASHINT2(HALF_MAX_INT,H.hash i)
+ | Branch (b,i,l,r) -> HASHINT4(b,i,HNode.hash l, HNode.hash r)
+ end
+ ;;
+
+ type t = HNode.t
+ let hash = HNode.hash
+ let uid = HNode.uid
-let rec norm n =
- let v = { id = gen_uid ();
- key = Node.hash_node n;
- node = n }
- in
- WH.merge pool v
-
-(* WH.merge pool *)
-
-let branch p m l r = norm (Branch(p,m,l,r))
-let leaf k = norm (Leaf k)
-
-(* To enforce the invariant that a branch contains two non empty sub-trees *)
-let branch_ne = function
- | (_,_,e,t) when is_empty e -> t
- | (_,_,t,e) when is_empty e -> t
- | (p,m,t0,t1) -> branch p m t0 t1
-
-(********** from here on, only use the smart constructors *************)
-
-let zero_bit k m = (k land m) == 0
+ let empty = HNode.make Empty
+
+ let is_empty s = (HNode.node s) == Empty
+
+ let branch p m l r = HNode.make (Branch(p,m,l,r))
-let singleton k = if k < 0 then failwith "singleton" else leaf k
+ let leaf k = HNode.make (Leaf k)
-let rec mem k n = match n.node with
- | Empty -> false
- | Leaf j -> k == j
- | Branch (p, _, l, r) -> if k <= p then mem k l else mem k r
-
-let rec min_elt n = match n.node with
- | Empty -> raise Not_found
- | Leaf k -> k
- | Branch (_,_,s,_) -> min_elt s
+ (* To enforce the invariant that a branch contains two non empty sub-trees *)
+ let branch_ne p m t0 t1 =
+ if (is_empty t0) then t1
+ else if is_empty t1 then t0 else branch p m t0 t1
- let rec max_elt n = match n.node with
+ (********** from here on, only use the smart constructors *************)
+
+ let zero_bit k m = (k land m) == 0
+
+ let singleton k = leaf k
+
+ let is_singleton n =
+ match HNode.node n with Leaf _ -> true
+ | _ -> false
+
+ let mem (k:elt) n =
+ let kid = H.uid k in
+ let rec loop n = match HNode.node n with
+ | Empty -> false
+ | Leaf j -> H.equal k j
+ | Branch (p, _, l, r) -> if kid <= p then loop l else loop r
+ in loop n
+
+ let rec min_elt n = match HNode.node n with
+ | Empty -> raise Not_found
+ | Leaf k -> k
+ | Branch (_,_,s,_) -> min_elt s
+
+ let rec max_elt n = match HNode.node n with
| Empty -> raise Not_found
| Leaf k -> k
| Branch (_,_,_,t) -> max_elt t
-
+
let elements s =
- let rec elements_aux acc n = match n.node with
+ let rec elements_aux acc n = match HNode.node n with
| Empty -> acc
| Leaf k -> k :: acc
| Branch (_,_,l,r) -> elements_aux (elements_aux acc r) l
in
- elements_aux [] s
-
+ elements_aux [] s
+
let mask k m = (k lor (m-1)) land (lnot m)
-
+
let naive_highest_bit x =
assert (x < 256);
let rec loop i =
if i = 0 then 1 else if x lsr i = 1 then 1 lsl i else loop (i-1)
in
- loop 7
-
+ loop 7
+
let hbit = Array.init 256 naive_highest_bit
-
- let highest_bit_32 x =
- let n = x lsr 24 in if n != 0 then Array.unsafe_get hbit n lsl 24
- else let n = x lsr 16 in if n != 0 then Array.unsafe_get hbit n lsl 16
- else let n = x lsr 8 in if n != 0 then Array.unsafe_get hbit n lsl 8
- else Array.unsafe_get hbit x
-
- let highest_bit_64 x =
- let n = x lsr 32 in if n != 0 then (highest_bit_32 n) lsl 32
- else highest_bit_32 x
-
- let highest_bit = match Sys.word_size with
- | 32 -> highest_bit_32
- | 64 -> highest_bit_64
- | _ -> assert false
- let branching_bit p0 p1 = highest_bit (p0 lxor p1)
+ let highest_bit x = let n = (x) lsr 24 in
+ if n != 0 then Array.unsafe_get hbit n lsl 24
+ else let n = (x) lsr 16 in if n != 0 then Array.unsafe_get hbit n lsl 16
+ else let n = (x) lsr 8 in if n != 0 then Array.unsafe_get hbit n lsl 8
+ else Array.unsafe_get hbit (x)
+
+IFDEF WORDIZE64
+THEN
+ let highest_bit64 x =
+ let n = x lsr 32 in if n != 0 then highest_bit n lsl 32
+ else highest_bit x
+END
+
+
+ let branching_bit p0 p1 = highest_bit (p0 lxor p1)
+
let join p0 t0 p1 t1 =
let m = branching_bit p0 p1 in
- if zero_bit p0 m then
- branch (mask p0 m) m t0 t1
- else
- branch (mask p0 m) m t1 t0
-
+ if zero_bit p0 m then
+ branch (mask p0 m) m t0 t1
+ else
+ branch (mask p0 m) m t1 t0
+
let match_prefix k p m = (mask k m) == p
-
+
let add k t =
- let rec ins n = match n.node with
+ let kid = H.uid k in
+ let rec ins n = match HNode.node n with
| Empty -> leaf k
- | Leaf j -> if j == k then n else join k (leaf k) j n
+ | Leaf j -> if H.equal j k then n else join kid (leaf k) (H.uid j) n
| Branch (p,m,t0,t1) ->
- if match_prefix k p m then
- if zero_bit k m then
+ if match_prefix kid p m then
+ if zero_bit kid m then
branch p m (ins t0) t1
else
branch p m t0 (ins t1)
else
- join k (leaf k) p n
+ join kid (leaf k) p n
in
ins t
let remove k t =
- let rec rmv n = match n.node with
+ let kid = H.uid k in
+ let rec rmv n = match HNode.node n with
| Empty -> empty
- | Leaf j -> if k == j then empty else n
+ | Leaf j -> if H.equal k j then empty else n
| Branch (p,m,t0,t1) ->
- if match_prefix k p m then
- if zero_bit k m then
- branch_ne (p, m, rmv t0, t1)
+ if match_prefix kid p m then
+ if zero_bit kid m then
+ branch_ne p m (rmv t0) t1
else
- branch_ne (p, m, t0, rmv t1)
+ branch_ne p m t0 (rmv t1)
else
n
in
(* should run in O(1) thanks to Hash consing *)
- let equal a b = a==b || a.id == b.id
-
- let compare a b = if a == b then 0 else a.id - b.id
+ let equal a b = HNode.equal a b
+ let compare a b = (HNode.uid a) - (HNode.uid b)
let rec merge s t =
if (equal s t) (* This is cheap thanks to hash-consing *)
then s
else
- match s.node,t.node with
- | Empty, _ -> t
- | _, Empty -> s
- | Leaf k, _ -> add k t
- | _, Leaf k -> add k s
- | Branch (p,m,s0,s1), Branch (q,n,t0,t1) ->
- if m == n && match_prefix q p m then
- branch p m (merge s0 t0) (merge s1 t1)
- else if m > n && match_prefix q p m then
- if zero_bit q m then
- branch p m (merge s0 t) s1
- else
- branch p m s0 (merge s1 t)
- else if m < n && match_prefix p q n then
- if zero_bit p n then
- branch q n (merge s t0) t1
- else
- branch q n t0 (merge s t1)
+ match HNode.node s, HNode.node t with
+ | Empty, _ -> t
+ | _, Empty -> s
+ | Leaf k, _ -> add k t
+ | _, Leaf k -> add k s
+ | Branch (p,m,s0,s1), Branch (q,n,t0,t1) ->
+ if m == n && match_prefix q p m then
+ branch p m (merge s0 t0) (merge s1 t1)
+ else if m > n && match_prefix q p m then
+ if zero_bit q m then
+ branch p m (merge s0 t) s1
+ else
+ branch p m s0 (merge s1 t)
+ else if m < n && match_prefix p q n then
+ if zero_bit p n then
+ branch q n (merge s t0) t1
else
- (* The prefixes disagree. *)
- join p s q t
-
-
-
+ branch q n t0 (merge s t1)
+ else
+ (* The prefixes disagree. *)
+ join p s q t
+
+
+
+
let rec subset s1 s2 = (equal s1 s2) ||
- match (s1.node,s2.node) with
+ match (HNode.node s1,HNode.node s2) with
| Empty, _ -> true
| _, Empty -> false
| Leaf k1, _ -> mem k1 s2
else
false
- let union s t =
- merge s t
+ let union s1 s2 = merge s1 s2
+ (* Todo replace with e Memo Module *)
+ module MemUnion = Hashtbl.Make(
+ struct
+ type set = t
+ type t = set*set
+ let equal (x,y) (z,t) = (equal x z)&&(equal y t)
+ let equal a b = equal a b || equal b a
+ let hash (x,y) = (* commutative hash *)
+ let x = HNode.hash x
+ and y = HNode.hash y
+ in
+ if x < y then HASHINT2(x,y) else HASHINT2(y,x)
+ end)
+ let h_mem = MemUnion.create MED_H_SIZE
+
+ let mem_union s1 s2 =
+ try MemUnion.find h_mem (s1,s2)
+ with Not_found ->
+ let r = merge s1 s2 in MemUnion.add h_mem (s1,s2) r;r
+
+
let rec inter s1 s2 =
if equal s1 s2
then s1
else
- match (s1.node,s2.node) with
+ match (HNode.node s1,HNode.node s2) with
| Empty, _ -> empty
| _, Empty -> empty
| Leaf k1, _ -> if mem k1 s2 then s1 else empty
if equal s1 s2
then empty
else
- match (s1.node,s2.node) with
+ match (HNode.node s1,HNode.node s2) with
| Empty, _ -> empty
| _, Empty -> s1
| Leaf k1, _ -> if mem k1 s2 then empty else s1
if zero_bit p1 m2 then diff s1 l2 else diff s1 r2
else
s1
-
-
-
+
(*s All the following operations ([cardinal], [iter], [fold], [for_all],
[exists], [filter], [partition], [choose], [elements]) are
implemented as for any other kind of binary trees. *)
-let rec cardinal n = match n.node with
+let rec cardinal n = match HNode.node n with
| Empty -> 0
| Leaf _ -> 1
| Branch (_,_,t0,t1) -> cardinal t0 + cardinal t1
-let rec iter f n = match n.node with
+let rec iter f n = match HNode.node n with
| Empty -> ()
| Leaf k -> f k
| Branch (_,_,t0,t1) -> iter f t0; iter f t1
-let rec fold f s accu = match s.node with
+let rec fold f s accu = match HNode.node s with
| Empty -> accu
| Leaf k -> f k accu
| Branch (_,_,t0,t1) -> fold f t0 (fold f t1 accu)
-let rec for_all p n = match n.node with
+
+let rec for_all p n = match HNode.node n with
| Empty -> true
| Leaf k -> p k
| Branch (_,_,t0,t1) -> for_all p t0 && for_all p t1
-let rec exists p n = match n.node with
+let rec exists p n = match HNode.node n with
| Empty -> false
| Leaf k -> p k
| Branch (_,_,t0,t1) -> exists p t0 || exists p t1
-let rec filter pr n = match n.node with
+let rec filter pr n = match HNode.node n with
| Empty -> empty
| Leaf k -> if pr k then n else empty
- | Branch (p,m,t0,t1) -> branch_ne (p, m, filter pr t0, filter pr t1)
+ | Branch (p,m,t0,t1) -> branch_ne p m (filter pr t0) (filter pr t1)
let partition p s =
- let rec part (t,f as acc) n = match n.node with
+ let rec part (t,f as acc) n = match HNode.node n with
| Empty -> acc
| Leaf k -> if p k then (add k t, f) else (t, add k f)
| Branch (_,_,t0,t1) -> part (part acc t0) t1
in
part (empty, empty) s
-let rec choose n = match n.node with
+let rec choose n = match HNode.node n with
| Empty -> raise Not_found
| Leaf k -> k
| Branch (_, _,t0,_) -> choose t0 (* we know that [t0] is non-empty *)
fold coll s (empty, false, empty)
-
-let rec dump n =
- Printf.eprintf "{ id = %i; key = %i ; node=" n.id n.key;
- match n.node with
- | Empty -> Printf.eprintf "Empty; }\n"
- | Leaf k -> Printf.eprintf "Leaf %i; }\n" k
- | Branch (p,m,l,r) ->
- Printf.eprintf "Branch(%i,%i,id=%i,id=%i); }\n"
- p m l.id r.id;
- dump l;
- dump r
-
-(*i*)
let make l = List.fold_left (fun acc e -> add e acc ) empty l
(*i*)
(*s Additional functions w.r.t to [Set.S]. *)
let rec intersect s1 s2 = (equal s1 s2) ||
- match (s1.node,s2.node) with
+ match (HNode.node s1,HNode.node s2) with
| Empty, _ -> false
| _, Empty -> false
| Leaf k1, _ -> mem k1 s2
false
-let hash s = s.key
-let from_list l = List.fold_left (fun acc i -> add i acc) empty l
+let rec uncons n = match HNode.node n with
+ | Empty -> raise Not_found
+ | Leaf k -> (k,empty)
+ | Branch (p,m,s,t) -> let h,ns = uncons s in h,branch_ne p m ns t
+
+let from_list l = List.fold_left (fun acc e -> add e acc) empty l
+
+
+end
+
+(* Have to benchmark wheter this whole include stuff is worth it *)
+module Int : S with type elt = int = Make ( struct type t = int
+ type data = t
+ external hash : t -> int = "%identity"
+ external uid : t -> int = "%identity"
+ let equal : t -> t -> bool = (==)
+ external make : t -> int = "%identity"
+ external node : t -> int = "%identity"
+
+ end
+ )
projects / SXSI / xpathcomp.git / blobdiff